The goal of this work is the development of an Alzheimer' s disease (AD) diagnostic brain scan. AD is caused by the deposition of arnyloid in the brain and a diagnostic brain scan for AD could be developed if amyloid imaging agents were made transportable through the blood brain barrier (BBB). This work will prepare a genetically engineered fusion protein wherein the amyloid-imaging agent is fused to a monoclonal antibody (MAb) that undergoes receptor-mediated transport across the BBB in vivo. This MAb has been genetically engineered in past work to enable use in humans without immunological reaction. The fusion protein will be a bi-functional molecule that not only crosses the BBB, but also binds to the amyloid plaques of AD brain in vivo. The fusion gene will be prepared in phase I. The phase H work will produce a cell line secreting the fusion protein, and this protein will be purified per GMP requirements. The bi-functionality of the fusion protein will be confirmed by immunoassay. At the completion of the phase II work, the company will be able to submit an IND to the FDA for testing of this novel in vivo brain scan that will be the first diagnostic test specific for AD.